Sedative peptides related to acth containing a d-phe moiety

ABSTRACT

The invention relates to novel peptides and peptide derivatives of the general formula:

United States Patent [191 Greven SEDATIVE PEPTIDES RELATED TO ACTH CONTAINING A D-PHE MOIETY [75] Inventor: Hendrik Marie Greven, Heesch,

Netherlands a [73] Assignee: Akzona Incorporated, Asheville,

[22] Filed: July 10, 1973 [21] Appl. No.: 377,978

[30] Foreign Application Priority Data July 15, 1972 Netherlands 7209839 [52] U.S. CL... 260/1125, 424/177, 424/179 [51] Int. Cl...C07c 103/52, A61k 27/00, A6 1k 17/0 6 [58] Field of Search 260/1125; 424/177, 179

[56] References Cited UNITED STATES PATENTS 3,228,927 1/1966 Kappeler et al. 260/1125 3,479,333 11/1969 Greven 260/1125 3,632,743 1/1972 Geller et al. 260/1125 Primary Examiner-Lewis Gotts Assistant Examiner-Reginald .1. Suyat Attorney, Agent, or Firm-Francis W. Young; Philip M. Pippenger; Hugo E. Weisberger 5 7 ABSTRACT The invention relates to novel peptides and peptide derivatives of the general formula:

[ Dec. 10, 1974 in which L and D indicate the configuration of the relative residue,

A stands for: HLMet, HLMet( O), H-LMet( 0 Dam, Dam( O), Dam( 0 or the moiety HLNHBCO, in which B is a branched or unbranched alkylene group with 1-6 carbon atoms,

Q respresents the group OH or Nl-l and X is selected from a (N-phenyl branched alkyl) amino group with the general formula as well as the functional derivatives thereof.

The above peptides and peptide derivatives accelerate the extinction of a condition avoidance response; that means that they can be used as sedative agents.

7 Claims, No Drawings SEDATIVE PEPTIDES RELATED TO ACIH CONTAINING A D-PHE MOIETY The present invention relates to peptides and peptide derivatives with psychopharmacological properties, in particular sedative properties.

From the Dutch Pat. application No. 70,10,052 it appears that the peptides DPhe (4l0) ACTH and DPhe -(4-9) ACTH accelerate the extinction of a conditioned avoidance response. This property of the said DPhe peptides presents a violent contrast to that of other (LPhe)ACTl-l peptide fragments which are known to inhibit the extinction of a conditioned avoidance response.

Up to now it has been assumed that the amino acid sequence (4-9)ACl"l-l with the amino acid residue phenylalanyl in the D-configuration was essential for exerting an acceleration of the extinction of avoidance response.

Surprisingly it has, however, been found that the sequence DPhe (4-9)ACTH is certainly not the key sequence for the said activity, but a much smaller peptide having the sequence DPhe (4-7 )ACFl-l on the understanding that both at the N-terminal as well as at the C-terminal side of that (key) peptide certain modifications can be introduced without affecting the activity of the peptide.

The present invention therefore comprises peptides and peptide derivatives of the general formula:

Q represents a hydroxy or amino group, and X is selected from a N-phenyl branched alkyl)-amino group of the general formula (in which R stands for a branched alkylene group with 2-6 carbon atoms, and R for hydrogen, hydroxy, halogen, or an alkyl or alkoxy 1-4 C) group) and the group PheY, in which Y represents a hydroxy group, a (N-aminoalkyU-amino moiety or the group LLys-Z or LArg-Z, in which 2 stands for a hydroxyl group, the group L-Phe-Ol-l, a (N-B-indolylalkyD-amino moiety or a (N-phenylalkyl)-amino moiety, as well as functional derivatives thereof.

The definition of D-X in the above general formula comprises besides the moiety -D--Phe-Y also a moiety that is substantially distinguished from the D- phenylalanyl residue by the absence of the carboxyl group. By a- D-(N-phenyl branched alkyl)-amino group 6 is meant in this connection the D-configuration of a residue of the general formula:

in which R represents a branched alkylene group with 26 carbon atoms, and R, hydrogen, hydroxy, halogen or a lower alkyl or alkoxy group with 1-4 carbon atoms.

Examples of this resiidue are a D-amphetamide group and a D-a-phenylethylamide group.

By a (N-aminoalkyl)-amino group in the definition of Y is meant a moiety that is mainly distinguished from the arginyl or lysyl residue by the absence of the carboxyl group, viz., a moiety of the formula:

in which Alk represents a branched or unbranched alkylene group with 2-6 carbon atoms, R hydrogen or alkyl (l-4 C), and R hydrogen, alkyl (14 C), or an amidine group.

A (N-B-indolylalkyD-amino moiety in the definition of Z is characterized by the formula:

in which Alk represents a branched or unbranched alkylene group with 1-6 carbon atoms. This moiety is substantially distinguished from tryptophan by the absence of the carboxyl group. An example of this moiety is a tryptamide group.

By a (N-phenylalkyl)-amino group in the definition of Z is meant a residue of the general formula:

in which Alk represents a branched or unbranched alkylene group with l-6 carbon atoms, and R hydrogen, halogen, hydroxy, or an alkyl or alkoxy group with 1-4 carbon atoms.

The key peptide DPhe (4-7)ACTH shows an acceleration of the extinction of avoidance response approximately at the same level as the known D-'Phe (4-9)ACTH peptide. This activity is not affected if the C-ter'minal D-Phe residue is replaced by a D-(N- phenyl branched alkyl)-amino residue.

The following modifications in the key peptide lead to a significant increase of the acceleration of extinction:

a. Replacement of Met by optically inactive residues,

especially the substitution of B-Ala or Dam for L- Met, causes an increase of activity by a factor of about 3,

b. Oxidation of the Met or Dam residue to the corresponding sulfoxide or sulfone causes an increase of acitivty by a factor 3l0,

c. Extension of the chain length at the C-terminal side by -LLys (or LArg)Phe-OH causes an increase of the activity by a factor of about 3,

(1. Extension of the chain length at the C-terminal side by -L-Lys (or L-Arg)-N-[?- indolylalkylamide, especially L-Lys (or L- Arg)-Tra raises the activity by a factor 340.

e. Extension of the chain length at the C-terminal side by an N-aminoalkylamide group or the group LLys (or L-Arg)-N-phenylalkylamide gives an increase of activity by a factor of about 3.

The peptides and peptide derivatives according to the general formula I are prepared by a process commonly used in peptide chemistry The processes that are employed usually for the manufacture of the present compounds can be summarised as follows:

a. condensation of a compound (amino acid, peptide) having a free carboxyl group and protected other reactive groups with a compound (amino acid, peptide or amine) having a free amino group and protected other reactive groups, in the presence of a condensation agent;

b. condensation of a compound (amino acid, peptide) having an activated carboxyl group and optionally protected other reactive groups, with a compound (amino acid, peptide, amine) having a free amino group and optionally protected other reactive groups;

c. condensation of a compound (amino acid, peptide) having a free carboxyl group and optionally protected other reactive groups with a compound (amino acid, peptide. amine) having an activated amino group and optionally protected other reactive groups,

after which the protecting groups are removed, if necessary.

Activation of the carboxyl group can be effected, for example, by converting the carboxyl group into an acid halide, an azide, anhydride imidazolide, or an activated ester such as the N-hydroxy-succinimide ester or the p-nitrophenyl ester.

The amino group can be activated by converting it into a phosphite amide or by the phosphor-azo" method.

The most conventional methods for the above condensation reactions are: the carbodiimide method, the azide method, the mixed anhydride method and the method of the activated esters, as described in The Peptides," Vol. I, l965 (Academic Press), by E. Schrdder and K. Liibke. Moreover Merrifields so called Solid Phase method, described in J. Am.

I Chem. Soc. 85, 2149 (1963) can be applied for the manufacture of the present peptides and peptide derivatives.

The reactive groups that are not allowed to participate in the condensation reaction are protected effectively by the so-called protecting groups, which can easily be removed again, e.g., by hydrolysis or reduction. For a description of the protecting groups there is referred to the literature on the subject.

It is mostly recommendable to protect also the guanidine group of arginine, the e-amino group of lysine and the imidazol group of histidine, but his protection is not necessary. Conventional protecting groups in this connection are a tert. -butyloxy-carbonyl or a tosyl group for the eamino group of lysine, a nitro group for the guanidine group of arginine and a benzyl, dinitrophenyl or a trityl group for the imidazol group of histidine.

The protecting groups can be split off by various conventional methods, dependent upon the nature of the 5 relative group, for example with trifluoro acetic acid,

or by mild reduction, for example with hydrogen and a catalyst such as palladium, or with l-iBr in glacial acetic acid.

Peptides according to the present invention having as the N-terminal moiety a L-Met( O) or Dam( O) residue may be prepared i.a. from the corresponding L-Metor Dam-peptide by means of a mild oxidation known per se, for example with dilute hydrogenperoxide or a peracid. This oxidation yields a mixture of the S- and R-sulfoxide, which mixture can be separated into the separate diastereo-isomers by a method known per se.

By coupling the S- or R-sulfoxide of methionine or desamino-methionine(Dam) with the peptide HL- Glu(Q)LHis-DX, in which Q and X have the meanings previously indicated, the separate enantiomers can also be obtained direct.

The peptides according to the invention having as the N-terminal moiety of L-Met( O or Dam(- O residue may be prepared most conveniently by an oxidation known per se of the corresponding L-Metor Dam-peptide, for example with H 0 or a peracid.

By functional derivatives of the peptides according to the general formula I are meant:

l. the pharmaceutically acceptable acid addition salts;

2. peptides according to the general formula I, in which one or more free amino groups have been substituted by an acyl group derived from an aliphatic carboxylic acid with 1-6 carbon atoms, such as an acetyl group;

3. unsubstituted amides or alkyl (l6 C) substituted amides of those peptides according to formula I having a free carboxyl group;

4. esters of the present peptides derives from aliphatic or araliphatic alcohols with 1-18 carbon atoms, in particular the lower (1-6 C) aliphatic alcohols, such as methanol, ethanol, butanol, or cyclohexanol, and the lower araliphatic (7-10 C) alcohols such as benzylalcohol, phenylethylalcohol or cinnamylalcohol;

5. metal complexes formed by contacting the peptides or the derivatives thereof with a sparingly soluble salt, hydroxide or oxide of a metal, preferably zinc, or preparations obtained by associating the relative peptides with organic, mostly polymeric, compounds such as gelatine, polyphloretinphosphate or polyglutamic acid.

The acid addition salts are obtained by reacting the present peptides with a pharmaceutically acceptable organic or inorganic acid such as l-lCl, phosphoric acid, acetic acid, maleic acid, tartaric acid and citric acid.

The peptides according to the invention and the derivatives defined above may be administered parenterally, orally, sublingually, rectally or intranasally. Preferably the peptides are placed in a form suitable for parenteral administration, for which purpose they are dissolved, suspended or emulgated in a suitable liquid. However, mixed with suitable auxiliaries and/or fillers, they can also be placed in a form suitable for oral, sublingual, rectal or intranasal administration.

The peptides or peptide derivatives according to the invention are preferably administered parenterally in a daily dosage of from 1 ,ug to 1 mg per kg bodyweight, dependent upon the peptids activity level. For oral, sublingual, rectal or intranasal administration the daily dosage may be considerably higher, preferably from 0.1 mg to 100 mg per kg/bodyweight.

Exceedingly valuable preparations are obtained if the present peptides are placed into a form in which they have prolonged activity, e. g., incorporated into gelatin, polyphloretinphosphate or polyglutamic acid, or preferably as metalcomplexes. These metal complexes can be obtained by contacting the peptides with poorly soluble metal salts, metal hydroxides or metal oxides. As poorly soluble metal salts the metal phosphates, metal pyrophosphates and metal polyphosphates are commonly used. Metals that can be used in this process are the metals belonging to the b-groups of the periodic system, for example cobalt, nickel, copper, iron, and preferably zinc, as well as the metals belonging to the main groups of the periodic system and capable of forming complexes, such as magnesium and aluminum. The preparation of the said metal complexes takes place in a conventional manner.

As already stated previously the compounds according to the invention have valuable psychopharmacological activities. They accelerate the extinction of a conditioned avoidance response; that means that they may be used in general as sedative or tranquillizing agents. More particularly they can be used for the treatment of mental disorders whereby an acceleration of the extinction is desired, for example in certain types of neurosis.

The psychopharrnacological activity of the present peptides was measured in the so-called Shuttle box test and in the Pole jumping" test. Both tests gave the same result as regards the accelerated extinction of the conditioned avoidance response.

With regard to the various abbreviations used throughout the specification, examples and claims, the following is to remark:

I. If no optical configuration has been stated the L- form is meant. II. The following abbreviations have been used for the protecting or activating groups:

2 benzyloxycarbonyl Boc tert-huty oxycarbonyl tBu tert.-butyl Me methyl ONP nitrophenyloxy Bzl ii enzyl III. For the solvents or reagents the following abbreviations have been used:

82 benzene To toluene EtOH ethanol g; butal ol ne Ac or HAc etic acid Am amylalcohol iPro isopropanol DMF dimethylformamide THF tetrahydrofuran TAA tri-ethylamine TFA trifluoro acetic acid Wa water DCCl dicyclohexyl carbodimide DCHU dicyclohexyl ureum IV. For the amino acid residues the following abbreviations have been used:

Met methionyl V Abbreviations used for other residues:

Dam desamjno-methion 1 (or y-methylthio- Dam( O) desamino-methionyl sulfoxide Dam( 0 desamino-methionyl sulfone PPA glphenylpropglhmino PEA B-phenyle y1)amino Amf (N-l-phenylisopropyl)amino. (derived from amfetamine) Tra (N-B-indolylethyUarnino, (derived from tryptamine) Preparation starting substances A. Preparation -Boc-Met-Glu(OtBu)HisN H l. Boc-MetGlu(OtBu)His--OMe BocMet-N H (10.52 g), dissolved in ml of DMF is cooled down to 0C, after which 23.6 ml of 3.4 N HCl in THF are added, and at 20C 5.85 ml (43.3 mmol) of isoamyl nitrite. The mixture is stirred for 7 minutes at 20C and then added to a solution of 17.05 g of HGlu(OtBu)l-lisOMe.2 HCl in 50 ml of dimethylformamide. Then enough triethylamine to adjust the final pH of the mixture to 6.9. The mixture is stirred for 3 days at 0C, after which the triethylaminel-lCl formed is filtered off, and the filtrate evaporated to dryness. The residue is dissolved in 150 ml of ethylacetate/water. The water layer is separated and the ethylacetate layer washed twice with water. Then the water layers are combined and extracted again with ethylacetate (2 X 25 ml). The ethylacetate layers are dried, after which the solution is evaporated to about ml and set aside at 0C.

Melting point: 138142C.

Rf in Bu:Ac:Wa (4:l:l) 0.59 on SiO Of the above methyl ester (3.7 g) are dissolved in 70 ml of methanol, after which 3.7 ml of hydrazine hydrate are added. The mixture is stirred for 5 hours at room temperature. The solution is evaporated to dry ness and the residue then stirred with water and dried.

Rf in AmzlprozWa (10:4:5) 0.39 on SiO B. Preparation BocVal-Glu(OtBu)-l-lisN l-l Boc-Val-OH (3.26 g; 15 mmol) is dissolved in 20 ml of methylene chloride, after which 1.73 g of N- hydroxy-succinimide are added. The mixture is cooled down to 20C, after which 3.09 g of DCCI, dissolved in 20 ml of cooled methylene chloride, are added. The resulting solution is stirred for 1 hour at 20C and then for 20 hours at +20C.

After filtration of the resulting DCHU, the filtrate is evaporated to dryness and the residue dissolved in 30 ml of DMF, after which 7.33 g of ZGlu(0t- Bu)l-lisOMe (prepared according to Kappler Helv.

The residue is dissolved in aqueous ethylacetate and the solution washed with water, sodium bicarbonate and water. The organic phase is dried, after which the ethylacetate is evaporated off in vacuo. The residue is recrystallized from ethylacetate/ ether.

Yield 3.95 g. Melting point: ll7l 19C.

Rf in Bz:EtOH (8:2) =0.S on SiO Of the above methyl ester 3.73 g are dissolved in 85 ml of methanol, after which 3.72 g of hydrazine hydrate are added. The mixture is stirred for 7 hours at room temperature, after which the solution is evaporated to dryness and the residue triturated with ether.

Rf in AmziProzWa (l0:4:5) 0.33 on SiO C. Preparation Boc-B-Ale-Glu(OtBu)His-N H 1n the same manner as described in B1 BocB-Ala-Glu(OtBu)l-lisOMe is prepared by coupling Boc-BAlaOH with l-lGlu(Ot- Bu)l-lis-OMe.

Melting point: 9395C.

Rf in BzzEtOH (8:2) 0.25 on SiO By condensing the substance obtained in l with hydrazine hydrate as described in E2 the peptide Boc,B--AlaGlu(OtBu)-l-lis-N l-l is obtained.

Rf in AmziProzWa (:4:5) 0.42 on SiO D. Preparation Boc-Gly-Glu(OtBu)-HisN H In the same manner as described in B.l Boc-G1y- Glu(OtBu)His OMe is prepared by reacting Boc- Gly- OH with H G ll l(0l ll- His- 0M6.

Melting point: 103-108C.

Rf in BzzEtOl-l (8:2) 0.43 on SiO By reacting this substance with hydrazine hydrate as described in A2 the BocGlyGlu(Ot Bu) His Nzk mra Rf in Am:iPro:Wa (10:4:5) 0.32 on SiO E. In the same way are also prepared:

1 Boc-A1aGlu( OtBu )-HisN l-l Rf=0.33 (Am:iPro:Wa 10:4:5). 2. Boc(a-Me)AlaG1u(OtBu)His-N l-l Rf= 0.31 (AmziProzWa 101425). 3. DamGlu( OtBu )--HisN H Rf= 0.52 (Bu:Ac:Wa 4:1:1). 4. Boc--Met-GlnHis-N H Rf= 0.28 (AmziProzWa 10:4:5).

EXAMPLE I To 2.34 g of BocMet-Glu(OtBul-lisN H dissolved in 25 ml of DMF are added, after cooling the solution to 0C, 2.3 m1 of 5.2 N l-lCl/THF and, after cooling to C, 0.54 ml of isoamyl nitrite. After 20 minutes stirring at -20C 1.7 ml of triethylamine and a solution of 0.86 g of HDPheOtBu in 20 ml of DMF are added, after which the pH is adjusted to 6.8.

After hours stirring at 0C the reaction mixture is filtered and the filtrate evaporated to dryness.

The residue is dissolved in ethylacetate/water and washed twice with water. The organic phase is dried and then evaporated. The residue is crystallized from ethylacetate/petroleum ether.

Yield: 2.44 g

Rf in Bu:Py:Ac:Wa (4:3/4: 1/411) =O.91 on SiO 2. Removal of protecting groups One gram of the tetrapeptide (1.) is dissolved in 10 ml of trifluoro acetic acid. The resulting solution is left to stand for 30 minutes at 20C and then added dropwise to ml peroxide-free ether.

The resulting precipitate is dried over KOH, dissolved in 25 ml of t-butanol/water (lzl) and stirred with Dowex X-8 in the acetate form. After filtration the filtrate is lyophilised.

Yield: 06 g of the acetate.

Rf in Bu:Py:Ac:Wa (2:3/411/4z1) 0.32 on SiO 3. In the same way as described in (1.) and (2.) the following peptideacetates are prepared starting from BocMetGlu(OtBu)l-lis-N H and H-D- Phe-OC ,H H-DPheOMe or D-amphetamine:

EXAMPLE ll a. Oxidation of l-l-MetGluHisDPhe-OH to the corresponding sulfoxide Of the tetrapeptide prepared in example 1.2 0.06 mmol is dissolved in 2.5 ml of acetic acid, after which 15 ,ul of 30% hydrogen peroxide are added. After 1 hours stirrage at 20C a suspension of 20 mg of platinum black in 2.5 ml of glacial acetic acid is added, after which the mixture is stirred for another 30 minutes.

After filtration the filtrate is evaporated in vacuum. The residue is dissolved in 10 ml of t-butanol/water (1:1 and lyophilized, after which the resulting sulfoxide is stored over P 0 Rf in Bu:Py:Ac:Wa (4:3/4:1/4:1) 0.22 on SiO b. Oxidation of l-lMetG1u-HisDPhe-OH to the corresponding sulfone Of the tetrapeptide prepared in example ll 02 mmol is dissolved in a mixture of 0.5 ml of water, 0.1 ml of 4N perchloric acid and 0.02 ml of 0.5M ammonium molybdate, after which 0.06 ml of 30% hydrogen peroxide is added. The mixture is stirred for 3 hours at 20C, after which 20 ml of tbutanol/water are added and Dowex X-S in the acetate fomi. The mixture is stirred for 1 hour and then filtered. The filtrate is ly ophilized.

Rf in BuzPyzAczWa (4:3/4:1/4:l) 0.23 on SiO EXAMPLE lll Boc-MetGlu(OtBu )--HisN l-l (1.17 g) is converted into the corresponding azide in the way described in example 1.1. After the addition of 0.9 g of H-DPheLys(B0c)Ol-l (Rf in BuzPyzAczWa (4:3/4z1/4c1) =0.30 on SiO the pH is adjusted to 7.1 with triethylamine and the reaction mixture set aside at C.

The reaction mixture is left to stand for 70 hours and then filtered, the filtrate evaporated in vacuo and the residue taken up in aqueous ethylacetate. The organic phase is washed with saliferous water, dried and distilled ofi in vacuo. The residue is dissolved in ethylacetate and diluted with petroleum ether. The resulting precipitate is filtered off.

Yield: 0.7 g.

Rf in TozEtOH (8:2) 0.25 on SiO 2. HMet-GluHisDPheLys-OH The protecting groups of the product obtained in l.) are removed in the way described before (example 1.2) after which the product is converted into the acetate yielding the pentapeptide acetate. Yield: 0.4 g.

Phe-OH l. BocAlaGlu(OtBu)His-D-Phe-OtBu Starting from 1.05 g (2 mmol) Boc-Ala--Glu(Ot- Bu)HisN H the azide is prepared in the conventional manner (example 1.1 The azide is added to 0.44 g of HD--PheOtBu, after which the pH is adjusted to 6.9 with triethylamine. The reaction mixture is stirred for 70 hours and then processed in the way described 'in example 1. 1.

Yield: 0.93 g. Rf in Bu:Py:Ac:Wa (4:3/411/4z1) 0.90 on SiO 2. In the same way are prepared starting from the relative hydrazine:

Boc-Val-Glu(OtBu)His-DPheOtBu Boc/3AlaGlu(OtBu)His--DPheOtBu DamGlu(OtBu)-HisD-PheOtBu BocMetGlnHis-D--PheOtBu. 3. Removal of protecting groups In the same way as described for the Met-analogue (example 1.2) the tetrapeptide analogues prepared in l. and 2. are deprotected, resulting into the acetates of the following peptides:

Boc/3Ala-Glu(OtBu)-His-N H (1.05 g) is converted in the manner described in example [.1 into the azide.

The azide is added to a cooled solutuion of H--D-- PheLys(Boc)-OH (see example Ill. 1 after which the pH of the reaction mixture is adjusted to 7.0 with triethylamine. The reaction mixture is stirred for 74 hours at 0, after which it is processed further in the way described in example Ill. 1.

Rf in Bu:Py:Ac:Wa (4:3/4:l/4:l) =0.87 (SiO Yield: 0.85 g.

2. Removal of protecting groups The pentapeptide (0.5 g) obtained in (1.) is dissolved in trifluoro acetic acid as described previously (example 1.2). The trifiuoro acetic acid-salt obtained is dissolved in t-butanol water and treated with Dowex X-8 (acetate). The resulting filtrate is lyophilised. Yield: 0.35 g. Rf in Bu:Py:Ac:Wa (4:3/4:l/4:1) 0.17 on SiO 3. In the same way are prepared the acetates of:

Rf in Bu:Py:Ac:Wa (4:3/411/4: 1) on SiO v EXAMPLE V1 A-GluHisDPheArgOl-l l. H-D-Phe-Arg-OH acetate A solution of 12.8 g of HArg(NO )OMe.HCl in 200 ml of DMF is cooled down to 4C after which 4.8 g of TAA are added. The resulting TAA.hydrochloride is filtered off, after which 20 g of Z-D-Phe-ONP are added.

After 4 days stirring at 20C, 100 ml of DMF are distilled off in vacuo and the residue is diluted with 600 ml of ethylacetate.

The organic phase is washed with citric acid (5%), ammonium-hydroxide and water, and after that dried. Then the solvent is evaporated. The light yellow residue is recrystallized from ethylacetate/petroleum ether.

Yield: 24 g. Melting point: 90-92c.

Rf in TozEtOH (8:2) 0.58 on SiO Twenty grams of this ester are dissolved in dioxane and then saponified with 1.1 equiv. sodiumhydroxide for 2 hours while stirring. After being acidified to pH 2, the dioxane is diluted with a tenfold quantity of water to precipitate the dipeptide.

The resulting precipitate is stirred for 3 hours at 0 and then filtered off.

Yield: 14 grams.

Rf in To:EtOH (8:2) =0.09 on SiO Ten grams of this dipeptide acid are dissolved in 200 ml of 90% acetic acid, after which 1 g of 10% palladium on charcoal is added. Hydrogen is bubbled through the mixture for 2 days. After filtration of the catalyst, the filtrate is evaporated to dryness, yielding 2 g of H-D-Phe-ArgOH.acetate.

Rf in BuzPy-AczWa (4:3/411/421) =O.20 on SiO To Boc--MetGlu(OtBu)-His-N prepared in the conventional manner (example 1.1) 4 mmol H-D-Phe-Arg-OH acetate (1) are added, after which the pH is adjusted to 7.1 with triethylamine. The mixture is stirred for hours at 0C and then filtered.

The filtrate is evaporated.

The residue is stirred with ethyl acetate andfiltered. Then the residue is taken up in DMF and added dropwise to dry ethylacetate. The mixture is stirred for 2 hours at 20C, after which the amorphous precipitate is filtered off, yield 60%.

Rf in Bz:EtOH (8:2) 0.15 on SiO 3. in the same way are prepared:

The acetates of the following peptides are obtained in 60-65% yield:

EXAMPLE Vll -ZDPheONP (9.24 g) is dissolved in 40 ml of DMF. After the addition of 4.77 g of HCl salt of B- c-NH(CH Nl-l in 60 ml of DMF and 2.88 ml of TAA. the mixture is stirred for 20 hours at 20C.

After removal of the resulting precipitate by filtration, the filtrate is evaporated to dryness.

The oily residue crystallizes from dry ethylacetate.

Yield after filtration of the precipitate: 90% (8.66 G). Rf in TozEtOH (8:2) =0.80 on $0,.

4.8 g of this protected amino acid-amide are dissolved in 100 ml of dry methanol. After the addition of 0.9 g of 10% palladium on charcoal, hydrogen is bubbled through the mixture for 2.5 hours, after which the mixture is filtered. The filtrate is evaporated to dryness.

Rf in BuzAczWa (4:125) 0.25 on SiO To the azide prepared from BocMet-Glu(0t- Bu)l-lisN l-l according to example 1.1 (5.85 g) are added 3.47 g of the derivative prepared in 1. and 3.76 ml of N-ethylmorpholine.

The pH is adjusted to 7.0, after which the mixture is stirred for 70 hours at 0C.

The resulting precipitate is filtered off, after which the filtrate is evaporated in vacuo. The residue obtained is taken up in aqueous ethylacetate, after which it is washed with water. Then the organic phase is dried and evaporated. The residue is crystallized from petroleum ether.

Rf in Bu:Py-Ac:Wa (4:3/4:1/4:l) =0.76 on SiO 3. Starting from the corresponding hydrazines the following peptides are prepared in the same way:

The peptides prepared in 2. and 3. are treated in the way as described in example 1.2 to obtain the acetates of the following peptides:

HLys(Boc)PheOBzl (9.68 g) is dissolved in 50 ml of DMF, after which 9.6 g of Z-DPheONP (22.8 mmol) are added. The mixture is stirred for 24 hours at 20C, after which the solvent is distilled off in vacuo and the residue taken up in ethylacetate.

The phase is washed successively with 0.1 N HCl, water, 5% sodium bicarbonate solution, water and then dried and evaporated in vacuo.

The resulting residue is ethylacetate/petroleum ether.

Rf in Bz:EtOl-l (8:2) 0.70 on SiO l-lLys( Boc)-PheOMe (4.24 g) is dissolved in 25 ml of DMF, after which 4.77 g of 2- D- Phe-ONP are added. The mixture is processed further as described in l.

Rf in BzzEtOl-l (812) 0.75 on SiO Of the ester obtained in 2. 500 mg are dissolved in methanol. The solution is cooled down to 0C. after which the solution is saturated with ammonia. After 24 hours stirring the resulting precipitate is filtered off and immediately processed further.

4. BOC)- Phe 1 3 H33 Three grams of ZDPhe-Lys(Boc)PheOH. obtained by saponification of the ester from (1.), are dissolved in 45 ml of DMF, after which 1.1 equiv. of undecylbromide and 1.1 equiv. of dicyclo-hexylamine are added. The mixture is stirred for 2 days at room temperature, after which the suspension is cooled down to 0C. After that the precipitate is filtered off. The filtrate is evaporated to dryness and the residue taken up in aqueous ethylacetate The organic phase is washed successively with 0.1 N HCl, water, 5% sodium bicarbonate solution and water, after which the ethylacetate layer is dried and distilled off in vacuo. The residue is immediately used for fur ther conversions.

5. Removal of Z-protecting group Five grams of the tripeptide derivative. obtained in (l), (2), (3) or (4.) are dissolved in 50 ml of methanol, after which 0.5 g of 10% palladium on charcoal is added. For 4 hours hydrogen is bubbled through the mixture, after which the catalyst is filtered off. The fi1- trate is evaporated and the residue immediately processed further. In this manner the following peptide derivatives are obtained:

recrystallized from Boc(oz-Me)AlaGlu(OtBu)HisN l-l (0.96 g) is converted into the azide with 3 ml of 1 N l-ICl/THF and 0.13 ml of isoamyl nitrite, in the conventional manner. This azide is added to the solution of 1 mmol of l-lDPhe-Lys(Boc)-Phe-Ol-l in 10 ml of cooled DMF, after which the pH is adjusted to 6.9 with N- ethylmorpholine.

The mixture is left to stand for 70 hours at after which the precipitate is filtered off and the DMF solution (the filtrate) is added dropwise to a -fold quantity of water. The resulting precipitate is filtered off after 2 hours stirring.

Yield: 1.2 g.

Rf in BuzPyzAczWa (4:3/421/4z1) =0.53 on SiO 7. 1n the same manner as described in 6. the following protected peptides are obtained:

By treatment of the peptides obtained in (6.) and (7.) with 90% TFA, as described previously, and exchange of the resulting trifluoro acetate for acetate, the acetates are obtained of:

Rf in Bu:Py:Ac:Wa (4:3/411/411).

EXAMPLE 1X 3.19 g of Z-DPheLys(Boc)-Tra obtained from Z-DPhe-ONP and l-lLys(Boc)--Tra are hydrogenated in methanol as described in example V1115.

Rf in BuzAczWa (4: l: 1) 0.76 on SiO BocMetGlu(OtBu)His-N H (1.5 g) is converted into the azide with 3.84 ml of 2.51 N HCl/THF and 0.44 ml of isoamyl nitrite in the way described previously.

After the addition of 1.36 ml of TAA and 1.48 g of HDPheLys(Boc)-Tra, dissolved in ml of DMF and 0.32 ml of TAA, the pH is adjusted to 7.7. After 70 hours stirring at 0 the mixture is filtered and the DMF distilled off in vacuo. The oily residue is taken up in aqueous ethylacetate and washed with water, saliferous water, 0.1 N HCl and again with saliferous water.

After drying, the ethylacetate is evaporated to about 45 ml, yielding a precipitate.

One gram of the peptide prepared in (2.) is deprotected in the same way as described in example 1.2 and exchanged for acetate.

Yield after lyophilization: 0.6 g.

Rf in BuzPyzAczWa (2:3/4:1/4:1) 0.35 on SiO 4. Oxidation Oxidation with hydrogen peroxide in the way described in example ll.a and 11b respectively gives the methionine-sulfoxide analogue and the sulfone derivative respectively.

Sulfoxide derivative Sulfone derivative In the same way as described in (2.) and (3.) the following peptide acetates are obtained:

H,B-Ala-GluHisDPhe-Lys-Tra DamGIuHisDPhe-Lys-Tra.

EXAMPLE X In the same manner as described in example IX the peptide Boc-Met-Glu(OtBu)HisN H is converted into the azide and then coupled to l-lD-- Phe-Arg-Tra, resulting into the protected peptide Boc-MetGlu(OtBu)HisDPhe--ArgTra.

The latter peptide is treated with trifluoro acetic acid in the manner as described previously after which the trifluoro acetate salt of the peptide is converted to the acetate.

Rf in BuzPycAczWa (4:3/4zl/421) 0.18.

EXAMPLE XI AGluHisD-.PheLys-R (R aminoalkylamide) 1. ZDPheLys(Boc)PPA Z-DPheONP (7.61 g) is added to a solution of 6.39 g of H-Lys(Boc)-PPA, obtained by hydrogenation from the corresponding ZLys( Boc)PPA (melting point 7879C) in ml of DMF.

This light yellow solution is stirred for one night at room temperature, after which the DMF is distilled off in vacuo. The residue is dissolved in ethylacetate and this solution is washed with 5% potassium carbonate solution, water. 0.1 N hydrochloric acid and water. The organic layer is dried, after which the ethylacetate is distilled off and the residue crystallized from warm ethylacetate.

Yield: 11.4 g.

Rf in Ba1EtOH (8:2) 0.68 on SiO Of the dipeptide amide prepared in 1., 9.07 G are dissolved in ml of purified DMF and 4 ml of 4 N HCl. After the addition of 0.9 g of 10% palladium on charcoal, hydrogen is bubbled through the mixture for 4 hours, after which filtration takes place and the filtrate is evaporated to dryness.

Rf in Bu:Ac:Wa (4:1:1) 0.60 on SiO 3. 800- Met-Glu(OtBu) l-lis D- Phe- Lys(Boc) -PPA 7 BocMetGlu(OtBu)-HisN H (2.34 g) is converted into the azide in the way described previously (example 1.1). Then so much solvent is added to the azide solution that the volume is exactly 40 ml (4 mmol azide-containing solution). To 10 ml of azide solution is added a solution of 1 mmol of the peptide derivative prepared in 2. in l0 ml of DMF, after which the pH is adjusted to 6.9-7.0 with N-ethylmorpholine.

After 70 hours stirring the resulting precipitate is filtered off and the filtrate evaporated to dryness in vacuo. The residue is stirred with water and dried. The resulting peptide derivative is crystallized from warm ethylacetate.

Rf in TozEtOH (8:2) 0.37 on SiO 4. H-Met-GluHisDPheLys-PPA.acetate Of the peptide derivative (prepared in 3.) 0.5 g is deprotected in a conventional manner (example 1.2. The trifluoro acetate is converted with Dowex X-8 (acetate) into the corresponding acetate.

Rf in Bu:Py:Ac:Wa (2:3/4:l/4:l) =0.40 on SiO 5. Oxidation of HMetGluHisD Phe-LysPPA In the way described in example II the methionine sulfoxide and sulfone analogues are obtained.

Both products are purified by Craigs counter current distribution, system BuzAczWa (4:111).

EXAMPLE Xll just the pH of the mixture to 8.5. After that the volume 6 is completed with distilled water to 50 ml.

One millilitre of suspension suitable for injection contains:

30 pg of peptide mg of zinc mg of Na HPOflH O mg of NaCl mg of benzylalcohol In this way zinc suspensions are prepared of the following peptides:

What is claimed is:

l. A peptide of the formula: A- l.(ilu(Q) L-HisDX in which L and D indicate the configuration of the relative residue and A is selected from the group consisting of H- LMet, HLMet( O), HLMet 0 desamino-methionyl, desaminodesaminomethionyl( O), desamino-methionyl O and the moiety: H NB-CO-, in which B is alkylene having 1-6 carbon atoms;

Q is selected from the group consisting of hydroxy and amino;

X is selected from a (N-phenyl branched alkyl) amino group of the formula in which R is a branched alkylene group with 2-6 carbon atoms and R, is selected from the group con sisting of hydrogen and hydroxy; and the group -PheY in which Y is selected from the group consisting of hydroxy, descarboxy-lysyl, descarboxy-arginyl, LLysZ and LArgZ, in which Z is selected from the group consisting of hydroxy, LPhe0H,

B-indolyl-ethylamino, and a phenylalkylamino moiety of the formula in which Alk is alkylene with 1-6 carbon atoms and R, is selected from the group consisting of hydrogen and hydroxy;

and functional derivatives of said peptide selected from the group consisting of pharmaceutically acceptable acid addition salts, derivatives in which one or more free amino groups are substituted by acyl derived from an aliphatic carboxylic acid with 1-6 carbon atoms, unsubstituted amides or lower alkyl (16 C) substituted amides of those peptides having a free carboxyl group, esters derived from aliphatic or araliphatic alcohols with 1-18 carbon atoms, and metal complexes thereof.

2. A peptide according to claim 1 of the formula:

5 in which A, Q and Y have the meanings indicated in 1 p in which A and Q have the meanings indicated in claim in which A, Q and Z have the meanings indicated in 1 and T is Selected from LArg and y Claim and T is Selected from y and 6. A peptide according to claim 1 in which A is se- A peptide accordmg to Glam 1 of the formula: 5 lected from the group consisting of Met, desamino- IA L Glu(Q) L' HiS"DPhe TPhe OH methionyl and the corresponding sulfoxides and sulin which A and Q have the meanings indicated in claim 1 and T is selected from LArg and LLys. fones thereof' 5. A peptide according to claim 1 of the formula: A metal Complex of the P p and p p I rivatives as claimed in claim 1.

thylamino =o= 

1. A PEPTIDE OF THE FORMULA: A-L-GLU(Q)-L-HISD-X IN WHICH L AND D INDICATE THE CONFIGURATION OF THE RELATIVE RESIDUE AND A IS SELECTED FROM THE GROUP CONSISTING OF H-L-MET, H-L-MET(>O),H-L-MET(>O2), DESAMINOMETHONYL, DESAMINODESAMINO-METHIONYL(>O), DESAMINO-METHIONYL (>O2), AND THE MIETY: H2N-B-CO-, IN WHICH B IS ALKYLENE HAVING 1-6 CARBON ATOMS, Q IS SELECTED FROM THE GROUP CONSISTING OF HYDROXY AND AMINO, X IS SELECTED FROM A (N-PHENYL BRANCHED ALKYL) AMINO GROUP OF THE FORMULA
 2. A peptide according to claim 1 of the formula: A-L-Glu(Q)-L-His-D-Phe-Y in which A, Q and Y have the meanings indicated in claim
 1. 3. A peptide according to claim 1 of the formula: A-L-Glu(Q)-L-His-D-Phe-T-Z, in which A, Q and Z have the meanings indicated in claim 1, and T is selected from L-Lys and L-Arg.
 4. A peptide according to claim 1 of the formula: A-L-Glu(Q)-L-His-D-Phe-T-Phe-OH, in which A and Q have the meanings indicated in claim 1 and T is selected from L-Arg and L-Lys.
 5. A peptide according to claim 1 of the formula: A-L-Glu(Q)-L-His-D-Phe-T-Indolylethylamino in which A and Q have the meanings indicated in claim 1 and T is selected from L-Arg and L-Lys.
 6. A peptide according to claim 1 in which A is selected from the group consisting of Met, desamino-methionyl and the corresponding sulfoxides and sulfones thereof.
 7. A metal complex of the peptides and peptide derivatives as claimed in claim
 1. 